Abstract

The Gulf of Mexico (Gulf) red snapper (Lutjanus campechanus) fishery is a $12 million industry. However, due to commercial and recreational exploitation, and bycatch from the shrimp fishery, this natural resource has become severally depleted. Fishery managers have implemented plans to rebuild the red snapper population, but have not been entirely successful. While genetic data has confirmed red snapper as a single stock, recent findings have shown demographic differences for red snapper across the Gulf, leading to separate management units east and west of the Mississippi River. The primary purpose of this study is to estimate the sources of recruits to the southeast Texas continental shelf by developing “signatures” from otolith trace elemental and stable isotope analysis. Age-0 red snapper were sampled during the fall of 2005 and 2006, and natural tags were established for six different nursery regions in the Gulf. Sub-adult and adult red snapper were sampled during the summer of 2006 and 2007 for four of the six regions. Otolith cores from the adults were extracted via a precision micro drill and processed using analytical techniques identical to those for age-0 otoliths. Cores will be compared to juvenile otoliths, and maximum likelihood models will be computed to estimate the nursery of origin of adults. The data will be used to estimate mixing and connectivity between different regions of the Gulf.

PDF Preview